Wideband circularly polarized microstrip antenna array using a new single feed network

A new single feed system is presented for broadband and high gain circularly polarized stacked microstrip (CPSM) array applications. It consists of a combination of a microstrip line and a via. The gap between elements and location of the feed are optimized to achieve a good circular polarization (CP) performance with high gain. A 2 x 2 sequentially rotated array was fabricated and tested. The measured 3 dB axial-ratio (AR) bandwidth is 27% (3.5-4.6 GHz) and at boresight gain is 9.0 dBic over the 3 dB AR bandwidth. The measured 10 dB return loss impedance bandwidth is around 51% (3.28-5.54 GHz). The proposed new feeding network system is very useful to design the high gain and wideband CP array ha a space-limited environment. (C) 2008 Wiley Periodicals, Inc.